3-D-Printed Wideband Circularly Polarized Dielectric Resonator Antenna With Two Printing Materials

A new 3-D-printed wideband circularly polarized (CP) dielectric resonator antenna (DRA) with two printing materials is investigated. The DRA has a multilayer comb-shaped structure at its top for generating CP fields. Three dielectric strips are embedded inside the DRA body to support multiple transverse-electric (TE) DRA modes to widen the DRA bandwidth. To slightly improve the axial-ratio (AR) performance, the DRA is twisted in the horizontal plane. For demonstration, a prototype operating in C-band was designed and printed with two different materials. The reflection coefficient, AR, radiation pattern, antenna gain, and efficiency of the antenna are measured, and reasonable agreement between the measured and simulated results is observed. The prototype has a measured 10 dB impedance bandwidth of 69.7% (4.80-9.94 GHz) and 3 dB AR bandwidth of 68.6% (4.52-9.24 GHz), achieving a wide overlapping bandwidth of 63.2% (4.80-9.24 GHz). Both the AR and overlapping bandwidths are record-high for a single-fed CP DRA. The prototype has a measured peak antenna gain of 8.3 dBic inside the overlapped passband.